An adjustable putter head assembly having a hosel attachment member that includes a hosel for receipt of a golf club shaft, a striking face, a bottom surface, and an adjustment surface that is generally parallel to the striking face and opposite the striking face. The hosel attachment member further includes an extension member that includes an aperture for mating with a threaded opening of the adjustment surface, and a plurality of receptacles that vertically extend the length of the extension member and correspond with a plurality of settings disposed on the adjustment surface. The adjustment surface defines multiple hosel position points for selectively attaching the hosel along the length of the putter head, and, adjusting the angular orientation between the golf club shaft and bottom surface in the plane in which the shaft lies.